Urban landscape lighting such as road lighting, street lighting, square lighting and so on is commonplace in many urban areas to provide illumination of such areas, which for instance is important for safety and security reasons. Many types of luminaires are used for urban landscape lighting, such as for instance post-top lighting, column lighting, bollard lighting and so on.
The functional lighting provided by such luminaries typically has to meet specific regulations in order to ensure that appropriate lighting levels are provided in a safe manner, e.g. by ensuring that glare levels produced by the luminaire are kept below defined thresholds.
Consequently, the design of such luminaires must be suitable to meet the aforementioned specific regulations. At the same time, because such luminaires are placed in urban environments, the appearance of such luminaires is important, for instance because the luminaire preferably has to blend into the environment in which it is placed. In other words, the luminaire preferably should be decorative whilst at the same time providing the required functional lighting in order to ensure that the luminaire is considered a welcome addition to the urban environment in which it is placed.
It has been recognized that the appearance of the luminaire in an urban landscape can be controlled not only by the appearance of the luminaire itself but also by shaping the luminous output of the luminaire. It is for instance is known to adjust the lighting pattern produced by a luminaire upon detection of a person in the vicinity of the luminaire. However, such dynamic variations of the lighting pattern may be beneficial for functional reasons but may not be considered aesthetically pleasing. In addition, the cost of such luminaires is significantly increased due to the requirement of motion detection sensors or the like and appropriate controllers responsive to such sensors that control the luminous output of the luminaire.
WO 2009/145883 A1 discloses a LED lighting fixture that includes a support structure having a horizontal cross-dimension and a top structure attached to the support structure and extending outwardly beyond the support structure. The top structure has a bottom surface with a peripheral portion surrounding a non-peripheral portion. A plurality of LED emitters is positioned on the peripheral portion for emitting light in downward direction substantially outside of the horizontal cross-dimension of the support structure. This luminous distribution of this fixture is claimed to be adaptable to meet the needs of a wide variety of (outdoor) lighting situations. However, these luminous distributions are entirely functional and do not target an aesthetically pleasing appearance.
US2010/239207A1 discloses an optical coupling device including a first parabolic reflector having an aperture at the first parabolic reflector vertex; a second parabolic reflector facing the first parabolic reflector; a light source positioned at the second parabolic reflector vertex; and a negative element located at the aperture for reducing the numerical aperture of the light emitted from the optical coupling device.